OSPF Multihoming creates suboptimal routing

I'm having situation whereby my customer CE2 is running multihoming. Both links need to be up all the times. However, on site, which is CE3 connected to the same PE (PE3). Attach network diagram to ease reference.

From CE3 going to CE2 of course it does follow directly based on OSPF 110 AD due to MP-iBGP 200 AD.